Verification method of a flight control system using a transportable wind tunnel

ABSTRACT

A transportable three-dimensional calibration wind tunnel system consisting of a small wind tunnel portion for creating a three-dimensional airflow having a suitable wind velocity, and a two-axis rotational deformation device portion for causing the wind tunnel portion to effect a conical motion with a nozzle blow port being in close proximity to an apex to suitably change a flow angle. The two-axis rotational deformation device includes a β-angle rotational deformation device having a β-angle deformation base supported to be rotated horizontally, and an α-angle rotational deformation device having an α-angle deformation base supported to be rotated vertically. A rotational axis of the α-angle deformation base, a rotational axis of the β-angle deformation base and a center axis of the small wind tunnel portion are arranged so that they intersect at a point. When verifying a flight control system of an aircraft using the transportable three-dimensional calibration wind tunnel system, the nozzle blow port of the three-dimensional calibration wind tunnel system is positioned at the extreme end of an air data sensor probe provided on the aircraft, and the three-dimensional calibration wind tunnel system and an on-board control computer of the aircraft are connected to an out-board control computer so that a suitable three-dimensional airflow is generated by the three-dimensional calibration wind tunnel system to verify the operation and function of the control surface in the stopped state on the ground.

This is a divisional of application Ser. No. 08/517,969 filed Aug. 22,1995, now U.S. Pat. No. 5,627,311.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to a transportable three-dimensionalcalibration wind tunnel system having a wind tunnel function, averification method of flight control system of an aircraft using saidtransportable three-dimensional calibration wind tunnel system,particularly an air active control aircraft which corresponds to thedisturbance detection (hereinafter merely referred to as an air activecontrol aircraft), and a flight simulator using said transportablethree-dimensional calibration wind tunnel system.

(2) Description of Related Art

Conventionally, as a system for evaluating various aerodynamicalcharacteristics and for testing and verifying air meters and thestrength of members in the development of aircraft, a wind tunnel isconsidered. The conventional wind tunnel is a large fixed facility. Anarticle to be tested is placed within a measuring portion of the windtunnel to perform the air test. Therefore, if the article to be testedis large, for example, such as an aircraft, the test can be made usingonly a scale model. Accordingly, for example, a Pitot or the like ismounted on a real airframe, in which state the air characteristicscannot be verified. Further, what sensor signal with respect to thechange in air the Pitot generates, and how the sensor signal istransmitted to a control system within the airframe are impossible toverify without a real flight test by utilizing a real airframe.

On the other hand, a flight simulator is used for training for thecontrol by a pilot of an aircraft or training for the operation of thesystem by a flight engineer. In the conventional flight simulator, inthe training situations the atmospheric conditions, such as for example,the atmospheric pressure, wind direction, wind speed and so on, and theflight conditions, such as the altitude, velocity, position, attitudeand so on, are predetermined or these conditions are suitably set froman instructor's operation panel whereby a motion simulation apparatus, acontrol loading simulation apparatus and a visual simulation apparatusare actuated in accordance with the program from the operationalsituations by the operation of control to conduct the training by way ofsimulation feeling. Accordingly, all the conventional flight simulationsare based on the predetermined data set. For example, the motion of anaircraft resulting from the actual change in air, which changes everysecond cannot be simulated.

Moreover, in the conventional flight simulator, the atmospheric data areset by forming the atmospheric data into a numerical model. However, itis difficult to completely form the actual atmosphere into a numericalmodel, and therefore there is a difference from the actual atmosphericconditions. Therefore, it is difficult to reproduce the same conditionsas the actual atmospheric disturbances, for example, such as a gust ofwind, a windshear or the like. Accordingly, it has been insufficient fortraining of a pilot to maintain stabilized flight in the event of beingcaught in the atmospheric disturbance as described.

On the other hand, with the recent advancement of a computer and controltechnology, there has been advanced by various countries research anddevelopment for an active control aircraft for positively controllingflight by way of a computer control with respect to change in air inorder to improve the safety and the comfortableness of the ride in theaircraft. Preferably, the verification of the control system in theactual flight of the air active control aircraft is accomplished byactually driving the airframe and generating a sensor signal withrespect to the atmospheric change. In the case of an extremely smallairframe, this can be done even by the conventional wind tunnel test butcannot be done in case of a real airframe. Further, actual flightevaluations cannot be made with the current state of research anddevelopment.

In view of foregoing, a system for performing the verification of acontrol system by sending a simulated electrical signal to the controlsystem in place of a real sensor signal is generally employed. Thissystem can suitably generate a signal in that if the system has aproblem which is difficult to cope with a signal different in propertiesfrom the real sensor signal, a time lag and so on, thus beingunsatisfactory as the verification system.

Further, the air active control aircraft presently under development isdirected toward detecting the motion state of the aircraft resultingfrom the change in air characteristics and to optimally control thecontrol surface and the engine thrust by means of a computer on thebasis of the detected results. Therefore, there occurs a time lagbetween a change in aerodynamic force and a control of the airframemotion. Accordingly, it is impossible to detect the change inaerodynamic force due to the sudden occurrence of the air disturbance toperform the flight stabilization control which corresponds to thedisturbance detection (hereinafter merely referred to as the flightstabilization control) before the airframe is affected thereby.

One of the reasons why the flight control cannot be made at the realtime in response to the change in air characteristics is that aerometers which are loaded on the real airframe to positively measure thechange in air characteristics during the flight have not yet beendeveloped.

Therefore, in the past, in the control of taking off and landing, apilot receives air information from a control tower to control theaircraft. However, control with a slight delay with respect to acrosswind, a gust of wind or windshear occurring suddenly sometimesleads to trouble. Therefore, it is necessary that the aircraft obtainthe air flight vector with respect to the change in air characteristicsin a real time, and to take it into the control system so that theflight motion caused by the change in air characteristics is accuratelypredicted to produce a control law for a fast-response air flightbalance control.

The present inventors have previously proposed a truncated pyramid-shapePitot probe capable of detecting an air velocity vector during theflying with a single probe and an air flight velocity vector measuringapparatus using the probe (see U.S. Pat. No. 5,423,209).

This invention solves the aforementioned problems encountered in thedevelopment of an air active control aircraft making use of theabove-described truncated pyramid-shape Pitot probe and the air flightvelocity vector measuring apparatus using the probe.

SUMMARY OF THE INVENTION

It is a first object of the present invention to provide a transportablethree-dimensional calibration wind tunnel system capable of generating athree-dimensional calibration airflow similar to a wind tunnel test withrespect to a real airframe to effect an air active test in connectionwith the real airframe.

It is a second object of the present invention to provide a verificationmethod of an air active control system capable of accurately performingthe verification of operation and function of a control surface withrespect to change in air, and the verification and evaluation of acontrol law or the like in connection with an aircraft, particularly anair active control aircraft in the stopped state on the ground using thethree-dimensional calibration wind tunnel system.

It is a third object of the present invention to provide a flightsimulator capable of simulating a flight motion on the basis of theactual change in air of a gust of wind.

The three-dimensional calibration wind tunnel system according to thepresent invention comprises a small wind tunnel portion for creating athree-dimensional calibration airflow having a suitable wind velocity,and a two-axis rotational deformation device portion for causing saidwind tunnel portion to effect a conical motion with a nozzle blow portacting as an apex to suitably change a flow angle. The small wind tunnelportion is comprised of an airflow generating tubular portion, ahoneycomb type straightener, and a nozzle, said airflow generatingtubular portion being provided with an axial fan constituting a movableblade, a stationary blade, and an electric motor for driving the axialfan. A multihole turbulence plate is detachably mounted on the blow portof the nozzle, if necessary.

The two-axis rotational deformation device is comprised of a β-anglerotational deformation device having a β-angle deformation basesupported to be rotated horizontally, and a α-angle rotationaldeformation device having a α-angle deformation base supported to berotated vertically. A rotational axis of the α-angle deformation base, arotational axis of the β-angle deformation base and a center axis of thesmall wind tunnel portion are arranged so that they intersect at apoint.

The two-axis rotational deformation device is preferably an active typetwo-axis rotational deformation device in which the α-angle deformationbase and the β-angle deformation base are controlled and driven by drivedevices, respectively, but may be of a passive type two-axis rotationaldeformation device in which the α-angle deformation base and the β-angledeformation base can manually set angles, and at least the α-angledeformation base has a free vibration mechanism comprised of a freevibration spring and an adjusting portion.

Further, the verification method of a flight control system of anaircraft according to the present invention is the verification methodof a flight control system for verifying on the ground the flightcontrol system of an aircraft on which is loaded an air flight velocityvector measuring device having an air data sensor probe, characterizedin that the nozzle blow port of the transportable three-dimensionalcalibration wind tunnel system comprising the small wind tunnel forcreating the three-dimensional calibration air having a suitable windvelocity and the two-axis rotational deformation device for causing thewind tunnel to effect a conical motion with the blow port being an apexto suitably change the flow angle is positioned at the extreme end ofthe air data sensor probe provided on the airframe, and thetransportable three-dimensional calibration wind tunnel system and anon-board control computer of the aircraft are connected to an out-boardcomputer to verify the operation and function of the control surface.

The aforementioned verification of the operation and function of thecontrol surface can be accomplished by the steps of: causing thetransportable three-dimensional calibration wind tunnel system togenerate the air disturbance on the basis of an air disturbance signalissued by the on-board control computer, detecting said air disturbanceby the air data sensor probe to thereby create a change in signal of athree-dimensional true airspeed detection system, generating controlamounts from various data bases stored in the on-board control computerand flight control law, and determining whether or not each controlsurface angle obtained by controlling the control surface amountadequately corrects the airframe motion due to the change in airimparted by the transportable three-dimensional calibration wind tunnelsystem.

Alternatively, the flight vector detected by the three-dimensional trueairspeed detection system is presented to a pilot by a monitor providedin a cockpit, and the control surface is allowed to effect motion bymeans of a signal generated by the manual operation of the pilot so asto evaluate and verify the controllability and to evaluate and verifythe control characteristics including the actions of the pilot. Inaddition, an air disturbance signal is generated by the on-board controlcomputer and an operation disturbance signal is generated whereby theevaluation and verification of the performance and the evaluation andverification of the operational characteristics including the action ofthe pilot can be also accomplished.

The aforementioned verification method for the flight control system canbe applied to not only an active control aircraft with an engine butalso an active control aircraft without an engine in which the airflight stabilization control is effected merely by the control-surfacecontrol.

The flight simulator according to the present invention comprises athree-dimensional calibration wind tunnel system composed of asimulation cockpit provided with a simulation operating seat and avisual simulation device, a motion simulation device for causing thesimulation cockpit to effect three-dimensional motion, a small windtunnel for creating a three-dimensional calibration airflow having asuitable airspeed and a two-axis rotational deformation device forcausing the wind tunnel to effect conical motion with a nozzle blow portat an apex, a three-dimensional true airspeed detection systemcomprising an air data sensor probe for detecting a three-dimensionalcalibration air generated by the three-dimensional calibration windtunnel system as air information and an air flight velocity vectorprocessor for operating the velocity vector from atmospheric informationdetected by the air data sensor probe, and a control command sectionhaving a flight simulator computer, characterized in that saidthree-dimensional calibration wind tunnel system and said air datasensor probe are arranged so that the extreme end of the air data sensorprobe is positioned in the central portion of the extreme end of thenozzle blow port, the three-dimensional calibration wind tunnel systemis controlled in air speed and direction of wind by a flow generatorcontrol computer, an output of the three-dimensional true airspeeddetection system is input into said flight simulation computer, and acontrol signal based on the flight velocity vector is sent to thesimulation cockpit and motion simulation device.

As the air data sensor probe, it is preferable to employ a truncatedpyramid-shape Pitot probe. The configuration is such that the flowgenerator control computer receives real flow information from a realairport, the three-dimensional calibration wind tunnel system iscontrolled according to the real wind information, and the airflowgenerator generates the same airflow as that of the real airport in realtime to effect simulation. Further, an aerodrome information of windcondition RAM is provided in the control command section and the windinformation of the real airport is input and stored in the aerodromeinformation of wind condition RAM whereby the flight simulator computercalls the wind information to generate the airflow conditions similar tothat of the real airport in the three-dimensional calibration windtunnel system to effect simulation.

Since the three-dimensional airflow generated by the three-dimensionalcalibration wind tunnel system is in a limited region of airspeed due tothe noise problem, the airflow generation ability and so on, apredetermined quantity of flight velocity vector signals from the airflight velocity vector processor are continuously shifted to generate asimulated airspeed different from the actually generated airspeed in thecontrol command in the control command section. A velocity vectorscaling processor scaling-processes the flight velocity vector signalfrom the operation processor on the basis of the aforementioned shiftamount, thereby enabling the simulation in a wide range of airspeeds.

The three-dimensional calibration wind tunnel system and the air datasensor probe may be loaded on the motion table of the motion simulationdevice or may be provided outside the motion table.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the transportable three-dimensionalcalibration wind tunnel system according to an embodiment of the presentinvention;

FIG. 2 is one enlarged view showing essential parts of the transportablethree-dimensional calibration wind tunnel shown in FIG. 1;

FIG. 3 is a partially sectional side view of a wind tunnel of thetransportable three-dimensional calibration wind tunnel system shown inFIG. 1;

FIG. 4 is a partially sectional side view of a nozzle blow port in thestate where the multi-hole turbulence plate is mounted;

FIG. 5 is a partially sectional side view of a nozzle blow port in thestate where the multi-hole turbulence plate is removed;

FIG. 6 is a schematic view showing the verification method of a flightcontrol system of an air active control aircraft with an engineaccording to another embodiment of the present invention;

FIG. 7 is a block diagram of the verification method of flight controlsystem shown in FIG. 6;

FIG. 8 is a schematic block diagram of the control signal generationsystem shown in FIG. 7;

FIG. 9 is a schematic view showing the verification method of flightcontrol system of an air active control aircraft without an engineaccording to a further embodiment of the present invention;

FIG. 10 is a perspective view of a truncated pyramid-shape Pitot probe;

FIG. 11 (a) is a schematic view of the air active control aircraftaccording to a further embodiment, and FIG. 11 (b) is an enlarged viewof the nose portion thereof;

FIG. 12 is a schematic side view of the flight simulator according toanother embodiment of the present invention;

FIG. 13 is a control block diagram thereof; and

FIG. 14 is a diagram showing the relationship between the set airspeedof the three-dimensional flow generation representative of the scalingfunction and the simulated airspeed after scaling process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 to 5 show various embodiments of the transportablethree-dimensional calibration wind tunnel system according to thepresent invention.

The transportable three-dimensional calibration wind tunnel system 1according to the present invention is composed of a small wind tunnelportion 2 for creating an airflow with even speed and direction of thewind and less variation in speed, and an active two-axis rotationaldeformation device 3 for causing the wind tunnel portion to effectconical motion with a nozzle blow port 14 being an apex to suitablychange a flow angle.

As shown in FIG. 3, the small wind tunnel portion 2 is composed of aflow generation tubular portion 5, a honeycomb type straightener 6, anda nozzle 7. The flow generation tubular portion 5 is provided with anaxial fan 8, a stationary blade 9, and a bearing 11 for supporting anelectrical motor 10 for driving the axial fan at a diametrically centralpart. The honeycomb type straightener 6 is provided with a straighteninghoneycomb 12 and a net 13. A multi-hole turbulence plate 15 (FIG. 4) ismounted on a nozzle blow port 14 of the nozzle 7, if necessary. A safetyprotective net 16 is provided at an inlet end of the flow generationtubular portion 5, if necessary. The electrical motor 10 is providedwith a suitable revolution indicator 17 for detection of the number ofrevolutions. It is to be noted that the flow generation tubular portion,the honeycomb type straightener and the nozzle are not necessarilyconstituted by separate members but may be formed integrally or may bedivided into a plurality of sections and connected with each other, asshown in the figure.

As clearly shown in FIGS. 1 and 2, the small wind tunnel portion 2 isinstalled on a base 20 through the active two-axis rotationaldeformation device 3 composed of an α rotational deformation deviceportion and a β rotational deformation device portion. The β rotationaldeformation device portion has one end whose central portion is securedto a β angle shaft 21 vertically supported on the base 20, while theother end thereof has a β rotational deformation base 24 to which issecured a β rotational deformation actuator 23 which is driven so as tomove along a circular guide rail 22 provided on the base 20, the βrotational deformation base 24 being provided to be rotated horizontallyabout the β angle shaft 21. In the present embodiment, the β angle guiderail 22 and the β rotational deformation actuator 23 constitute a linearmotor, which is rotated at a suitable angle in response to a signal froma control power supply device 42. Reference numeral 25 designates aguide roller provided at the end of the β rotational deformation baseand which is moved along the guide rail 22. Reference numeral 26designates a β angle stopper for securing the β rotational deformationbase 24 at a suitable angle on the guide rail, which is used whenmanually adjusted.

The α rotational deformation device portion has an α rotationaldeformation base 30, and an α-shaft fixed bracket 31 is stood upright onone end of the α rotational deformation base 30. An α-shaft 32 securedhorizontally to the α-shaft fixed bracket is supported on an α-shaftsupport bracket 27 stood upright on one end of the β rotationaldeformation base 24. The small wind tunnel portion 2 is placed on andsecured to the α rotational deformation base 30. An α rotationaldeformation actuator 33 secured to the tubular portion of the windtunnel and an α-angle guide rail 34 stood upright on the β rotationaldeformation base constitute a linear motor, and the α rotationaldeformation base 30 can be rotated at a suitable angle vertically aboutan α-shaft 32 in response to a signal from the control power supplydevice 42. Reference numeral 35 designates a manual α-angle stopper.

The α-shaft 32 and the β-shaft 21 are arranged so that their axesintersect at right angles, and the small wind tunnel 2 is secured to theα rotational deformation base 30 so that the nozzle axis of the smallwind tunnel 2 passes a point P where the α-axis and the β-axis intersectat right angles (FIG. 2) and a center point q of the nozzle blow port 14is positioned away from the point p by a predetermined distance L.Accordingly, the α rotational deformation base 30 and the β rotationaldeformation base 24 are rotated about the α-shaft 32 and the β-shaft 21whereby the nozzle axis can be set to a suitable angle within theconical portion about the center point q of the nozzle blow port.

In the present embodiment, the rotational angle of the α-shaft 32 isdetected by an encoder 36 provided on the α-shaft and is displayed on anα-angle dial plate 38 secured to the α-shaft support bracket 27 by apointer 37 provided on the end of the α-shaft. Similarly, the rotationalangle of the β-shaft 21 is detected by an encoder 39 provided on theβ-shaft and is displayed on an β-angle dial plate 41 secured to the base20 by a pointer 40 mounted on the β rotational deformation base 24.

While as the rotational deformation device, the linear motor device isemployed, it is to be noted that the device is not always limited to onedescribed in the present embodiment but a suitable device such as a ballscrew device, a cylinder device or the like can be employed. As analternative two-axis rotational deformation device, it is possible thatthe β rotational deformation base is provided on the α rotationaldeformation base reversely to the former construction, and the smallwind tunnel is placed on the β rotational deformation base. Further, thepower drive device need not necessarily be provided but the a angle andthe β angle may instead be suitably set manually.

In the case where the flow angle is set manually, in the presentembodiment, a free vibration mechanism comprising a free vibrationspring and an adjusting portion is provided, as clearly shown in FIG. 2,so that the free vibration and the period can be passively varied by theα angle. In FIG. 2, reference numeral 45 designates an operating platedetachably suspended from the α rotational deformation base 30. Springs47 and 47' are provided on spring mounting plates 46 and 46' adjustablystanding upright on the β rotational deformation base 24 through aadjusting flat plate 48 so as to sandwich the operating platetherebetween. The springs 47 and 47' are normally adjusted in theirposition so that the operating plate maintains its vertical state, thatis, the α angle rotational deformation base maintains its horizontalstate. The α rotational deformation base 30 can be maintained in thehorizontal state by longitudinally adjusting the adjusting flat plate48.

Accordingly, in the state shown in FIG. 1, in the state whererestriction caused by the actuator 33 and the stopper 35 is completelyreleased so that the small wind tunnel 2 can be rotated integrally withthe α rotational deformation base 30, when the small wind tunnel portion2 is pressed downward and released, the small wind tunnel portion 2freely vibrates about the α shaft 32 and becomes gradually attenuatedand stops in a horizontal state. The spring pressure can be adjusted byadjusting the spacing between the spring mounting plates 46 and 46' tosuitably adjust the rate of attenuation. In the case where therotational deformation device is controlled by the actuator, the freevibration device is removed.

The transportable three-dimensional calibration wind tunnel system isconstructed as described above. The output of the axial fan iscontrolled whereby an airflow without turbulence having a suitable speedof wind or an airflow in a turbulent state can be generated. Inaddition, the α rotational deformation device and the β rotationaldeformation device are suitably controlled whereby the direction of windof an airflow blown out of the nozzle blow port can be suitablycontrolled to generate an airflow having a large degree of turbulencefrom a suitable three-dimensional airflow and an airflow having a smalldegree of turbulence. Accordingly, it is possible to generate thethree-dimensional airflow having a wind speed and direction of wind asin a predetermined program.

Since the three-dimensional calibration wind tunnel system according tothe present invention can be constructed to be portable, it can be movedto a suitable place. Thus, it is possible to test an air sensor or thelike which is mounted on a real airframe, which has been impossible inthe conventional wind tunnel test.

The embodiment of the verification method of flight control system of anair active control aircraft having a three-dimensional true airspeeddetection system loaded thereon will be described hereinafter withreference to FIGS. 6 to 9.

First, in connection with the present embodiment, an embodiment of theair active control aircraft which is an object to be verified will bedescribed.

The active control device of the air active control aircraft 49 in thepresent embodiment is mainly composed of a control signal generationsystem comprising a truncated pyramid-shape Pitot probe 50, an airflight velocity vector processor 51, an on-board control computer 52 anda group of airframe motion detection sensors 53 such as a conventionalthree-axis gyro, an inertial reference unit and the like, a group ofvarious control actuators 54 for receiving a control signal from thecontrol signal generation system to drive various control surfaces, anda thrust control device 55 for controlling an output of the engine.

The truncated pyramid-shape Pitot probe 50 is provided to project fromthe extreme end of the aircraft, as shown in FIG. 6, in order todecrease an error in position and to quickly detect a change in airflowin the flight direction. The truncated pyramid-shape Pitot probe 50 hasan extreme end shaped in a truncated pyramid-shape and is provided atthe apex with a shield hole 57, as shown in FIG. 10. In the center ofthe probe there is arranged a total pressure tube 56 having a smallerdiameter than that of the shield hole, the shield hole 57 being providedat the bottom end with a branch hole 58 to allow a part of the pressurein the shield hole to leak. In each of square pyramid surfaces 59₁ to59₄ are formed a plurality of groups of pressure holes 60₁ to 60₄. Bypositioning the truncated pyramid-shape Pitot probe 50 at thethree-dimensional flow, it is possible to measure the total pressure Hof the total pressure tube 56 and pressures P₁ to P₄ of the groups ofpressure holes 60₁ to 60₄ on the truncated pyramid-surface.

While the truncated pyramid-shape Pitot probe 50 is normally formed as aseparate probe, as shown in FIG. 11A and FIG. 11B, it is to be notedthat the probe 50 can be provided directly on a nose portion 111 of asupersonic airframe 110, as shown in FIG. 11B. The construction of atruncated pyramid-shape 5-hole Pitot probe 112 is basically similar tothat of the probe described in the above-described embodiment, detaileddescription of which is therefore omitted.

The air flight velocity vector processor 51 is provided to process thevelocity vector from pressures detected by the truncated pyramid-shapePitot probe 50. As shown in the block diagram in FIG. 8, theaforementioned processor has a pressure sensor 62 for converting thepressure into an electrical signal and a ROM 63 which stores therein inadvance pressure coefficients for correcting pressure information of theprobe 50 obtained by experiments of the wind tunnel, and is composed ofa CPU 64 for processing the velocity vector from the pressureinformation on the basis of the velocity vector analyzing software.

According to the air flight velocity vector processor 51 of the presentembodiment, the total pressure H and differentials (H-P₁), (H-P₂),(H-P₃), and (H-P₄) can be obtained from the total pressure H measured bythe truncated pyramid-shape Pitot probe 50 and the pressures P₁ to P₄ onthe square truncated pyramid-surface. The operation can be executed onthe basis of the velocity vector analyzing software from the pressureinformations and the air temperature sensors to obtain the flightvelocity vectors of the true air velocity V, the elevation angle α andthe angle of sideslip β. That is, it is possible to grasp the directionof wind or the like in the flight condition in real time. Further, thealtitude h is obtained from static pressure to thereby obtain the rateof climb, and the Mach number is obtained from dynamic pressure andstatic pressure.

The on-board control computer 52 stores therein airframe and aerodynamicforce data bases obtained by the wind tunnel test or the like and enginedata bases obtained by the engine performance test in the form of ROMand receives therein programs for predicting the flight conditionsinduced with respect to the change in airflow on the basis of thecontrol rule and the flight rule from the aforementioned informations tocreate a flight control law for the air flight stabilization control.For example, as the airframe and aerodynamic data bases, necessary datasuch as a probe position error table including every elevation angle (αangle) and the angle of sideslip (β angle), a table of variouscoefficients of translational force (C_(L), C_(D), C_(T)) due to thechange in α/β angle, and a table of various moment coefficients(pitching, yawing, rolling) are stored in ROM. These data are selectedby inference, table look-up and interpolation to create the flightcontrol law for every flight configuration during takeoff, cruising andlanding.

The flight control law varies with the kind of airframes and varies withthe interference and operation procedures. Basically, however, the airflight velocity vector signals (such as the elevation angle α, angle ofsideslip β, altitude h signals) and airframe motion detection sensorsignals are taken in parallel into a control surface control closed loopsystem and an engine control closed loop system, and the air flightvelocity vector signal induced by the change in airflow is received topredict the flight motion so as to perform the feedback control orfeedforward control of the engine thrust and various control surfaces.

Thereby, for example, in the aircraft shown in FIG. 6, from the on-boardcontrol computer 52, an engine thrust control command is given to enginethrust control devices 64 and 65, and a control-surface control commandis given to control actuators 66 to 76 of main control blade surfacessuch as an elevator, a rudder and an aileron and secondary controlsurfaces such as a spoiler and a high lift device to control the engineand the control surfaces in order to obtain the speed, attitude,altitude, heading orientation and rate of climb (descent) necessary forthe stabilized flight of the aircraft with respect to the change inairflow. At the same time, an output from the on-board control computeris displayed on a monitor in a cockpit. If necessary, it is possible toseparate the air flight velocity vector signal from the air activecontrol system to perform manual control on the basis of the monitorinformation.

In order to allow the air active control aircraft constructed asdescribed above to fly in safety, the transportable three-dimensionalcalibration wind tunnel system is used, and the verification ofoperation and function of the control surfaces, the evaluation of theflight control law, the flight simulation of a gust of wind or the likeand the performance evaluation of controllability are carried out in thefollowing manner, in connection with the real airframe prior to flightand after repairs.

FIG. 6 is a conceptual view of the verification system of the flightcontrol system for the purpose as described above. The verificationsystem of the flight control system according to the present embodimentis composed of an air active control aircraft 49 which is an airframe tobe verified, a transportable three-dimensional calibration wind tunnelsystem 1 installed outside the airframe, an out-board control computer80, a monitor 81 and a cockpit simulator 82. The cockpit simulator 82 isprovided to feel and verify the motion of a airframe created by theoperation of various control surfaces resulting from the change in air.However, that is not always necessary in the present verificationsystem.

The out-board computer 80 stores therein 1 various air models forexample, such as air models at takeoff or at landing, and air turbulencemodels such as a gust of wind, cross-wind, wind shear, etc., forcontrolling the transportable three-dimensional calibration wind tunnelsystem to generate various three-dimensional airflows, 2 controlturbulence models such as an erroneous control by a pilot, and 3 controlsystem verification software for carrying out the verification of theflight control system by motion of the control surfaces on the basis ofthe results of the model information given to the air active controlaircraft 49.

The out-board computer 80 feeds a flow generation signal for generatinga suitable three-dimensional airflow such as air turbulence ofcross-wind, a gust of wind and so on to the transportablethree-dimensional calibration wind tunnel system 1 to control the latterand to bidirectional signal-bond with the on-board control computer 52of the air active control aircraft, and monitors the verification of theflight control system caused by various degrees of turbulence, theoperation of the on-board control computer and the motion of the airactive control aircraft.

The transportable three-dimensional calibration wind tunnel system 1 isinstalled on the extreme end of the truncated pyramid-shape Pitot probe50 of the air active control aircraft 49 to generate thethree-dimensional airflow whereby the truncated pyramid-shape Pitotprobe 50 can obtain simulated air information similar to air informationat the actual flight. In that case, the transportable three-dimensionalcalibration wind tunnel system 1 is installed so that the centralportion at the extreme end of the truncated pyramid-shape Pitot probe 50is positioned at the point p which is the intersection between the αshaft and the β shaft of the system whereby the three-dimensionalairflow generated by the transportable three-dimensional calibrationwind tunnel system 1 becomes the change in air received by the airactive control aircraft as it is. Accordingly, an output and a nozzleangle of the fan of the transportable three-dimensional calibration windtunnel system 1 are controlled on the basis of the control signal fromthe out-board control computer to thereby suitably create the change inairflow at the standing time received at the time of takeoff andlanding, at the time of climbing and descending or at the time ofcruising, or the simulated change in air similar to the air turbulencewhen the crosswind, a gust of wind, a wind shear, etc. occurred toimpart them to the truncated pyramid-shape probe 50 of the air activecontrol aircraft 49.

As will be described in detail later in the embodiment of the flightsimulator, in the present embodiment, a velocity vector scaling functionprocessor 83 is connected between the air flight velocity vectorprocessor 51 of the air active control aircraft 49 and the on-boardcontrol computer 52 at the time of verification in order to enable theverification of the flight control system in a flight region in excessof the generated airspeed ability of the transportable three-dimensionalcalibration wind tunnel system 1. The velocity vector scaling functionprocessor 83 is designed so that the shift magnification for shiftingthe actual generated airspeed by a suitable amount in the operationprocessing is set by the out-board control computer to correct thevelocity vector obtained by the air flight speed operation processor inaccordance with the shift magnification to provide a continuity wherebythe velocity vector at the shifted airspeed can be obtained.

The air flight velocity vector is calculated by the air flight velocityvector processor 51, similarly at the time of actual flight, from theair information obtained from the truncated pyramid-shape Pitot probe50. The resultant vector is taken into the closed loop control system inparallel with airframe motion detection sensor signals by the on-boardcontrol computer 52 to predict the flight motion induced by the changein air, and various control actuators are operated by the feedback orfeedforward control. At the same time, the control signal is applied tothe out-board cockpit simulator, the out-board control computer 80 andthe monitor 81. It is to be noted in this case that the thrust controldevice 55 for controlling the engine is placed in the inoperative stateand only the control actuators are controlled, but the control signal tobe fed to the thrust control device is moved to the out-board controlcomputer as it is for monitoring it.

As the verification method, whether or not the control surface anglesobtained by the control actuators quickly and adequately correct themotion of the airframe caused by the airflow changed by thetransportable three-dimensional calibration wind tunnel system 1 isverified by the out-board control computer on the basis of the controlsystem verification software stored in advance in the said computer.

Verification items include, for example, 1 verification of operation andfunction of the control surface, 2 evaluation of the degree of thecontrol surface angle and the control law of the response time from thechange in air to the change in the control surface angle, 3 verificationwhether or not the flight control law with respect to the air turbulenceof a gust of wind or the like given by the transportablethree-dimensional calibration wind tunnel system, and 4 evaluation andverification of the control performance of the air active controlaircraft by the closed loop control system including a pilot such thatthe motion of the air active control aircraft and the signal of the airflight velocity vector detection sensor are presented to the pilot bythe monitor of the cockpit, the control surface is moved by the controlsignal generated by the pilot's manual operation and the change inairflow is caused to occur in the transportable three-dimensionalcalibration wind tunnel system, and evaluation and verification of thecontrollability including actions of the pilot (for example, such as theoperating procedure of rudder and aileron resulting from the turning orthe like).

While in the foregoing, a description has been made of the embodiment ofthe verification system of the manned air active control aircraft, it isto be noted that the verification system of the present embodiment islikewise applied, as shown in FIG. 9, to the verification of an unmannedengine-less air active control aircraft 90 as a spacecraft underdevelopment now. FIG. 9 is a conceptual view of the verification systemof the air active control aircraft 90 which is combined with a systemsuch as a Global Positioning System (GPS) to enable the unmanned remotecontrol. A block diagram of the verification system shown in FIG. 9 isnot shown, but it is equivalent to a digram where the lift controldevice and the engine are removed, as shown in FIG. 7.

The air active control aircraft 90 is substantially similar to the airactive control aircraft 49 of the previously mentioned embodiment exceptthat the engine control closed loop is not provided, and that variousflight and navigation data of the output of the on-board controlcomputer are transmitted to the control room on the ground by a datatransmitter. Accordingly, in the figure, parts similar to those of theprevious embodiment are indicated by the same reference numerals asthose of the previous embodiment, detailed description of which isomitted. In the air active control aircraft 90 according to the presentembodiment, a control-surface control command is given to controlsurface actuators 97 to 101 for driving rudders 91, 92 elevons 94, 95and a body flap 96 by an output signal from the on-board controlcomputer 52, and the control surfaces are controlled to obtained theattitude, heading orientation and rate of descent so that the flightmotion induced by the change in air is predicted to enable the stabledescent/approach and landing.

One embodiment of the verification method of the flight control systemof the air active control aircraft according to the present inventionhas been described. Aircrafts applicable for the present invention maybe of any aircraft which is provided with an air data sensor probe suchas a normal civil aircraft, a helicopter, a supersonic airframe, VTOL,(Vertical Take-off and Landing Aircraft) an engine-less glider, and soon. The kinds of aircraft are not limited.

An embodiment of a flight simulator of the air active control aircraftmaking use of the transportable three-dimensional calibration windtunnel system according to the above-described embodiment will bedescribed hereinbelow in detail with reference to FIGS. 12 to 14.

FIG. 12 is an external view of a flight simulator 150 according to thepresent invention, and FIG. 13 is a block diagram showing the systemconstruction.

The flight simulator 150 according to the present invention is composedof a simulation cockpit 153 provided on a motion table 152 of a motionsimulation device 151 capable of applying a six-degrees of freedommotion by a combination of suitable actuators with a simulation controlseat device and a visual simulation device, a transportablethree-dimensional calibration wind tunnel system 154, a simulator bodyloaded with a three-dimensional true airspeed detection systemcomprising a truncated pyramid-shape Pitot probe 155 for detecting thethree-dimensional airflow generated by the three-dimensional calibrationwind tunnel system as air information and a three-dimensional trueairspeed detection system 157 comprised of an air flight velocity vectorprocessor 156 for operating the velocity vector from the airinformation, and a control command section 158 such as a controlcomputer installed in a flight simulator facility.

The transportable three-dimensional calibration wind tunnel system 1 andthe truncated pyramid-shape Pitot probe 155 are arranged in the relationsuch that the extreme end of the truncated pyramid-shape Pitot probe ispositioned in the central portion at the extreme end of the nozzle blowport similarly to FIG. 6.

The control command section 158 is composed of a flight simulatorcomputer 160, a velocity vector scaling function processor 161 forscaling-function processing a velocity vector from the air flightvelocity vector processor 156 on the basis of the scaling function of anairflow generator described later, a motion controller 162 forcontrolling the motion simulation device 151 by the output of the flightsimulator computer 160, an airflow generator computer 163 forcontrolling the driving of the transportable three-dimensionalcalibration wind tunnel system on the basis of an airflow generationcommand from the flight simulator 160, and a wind condition RAM 164.

Further, in the transportable three-dimensional calibration wind tunnelsystem of the flight simulator according to the present invention, notonly the flight simulator computer is allowed to generate an airflow onthe basis of airflow information preset to the flight simulator computerbut also the airflow generator control computer 163 is connected to awind information system 165 in an airport through a telemeter or opticalcommunication to receive airflow information (such as wind velocity,direction and altitude) generated in a real airport so that the sameairflow as that in the real airport is generated at real time to performthe flight simulation on the basis thereof. Further, the airflowinformation from the airport is divided, for example, every season andevery time, a number of which are stored in the wind condition RAM 164.Specific airflow information is called from the RAM by the simulatorcomputer when necessary to give it to the airflow generator controlcomputer whereby the flow generation conditions peculiar to the airportare reproduced by the three-dimensional calibration wind tunnel systemaccording to the season or time zone to enable the flight simulationtraining at the time of takeoff and landing.

Furthermore, the simulator according to the present invention has ascaling function capable of generating a simulation wind velocitydifferent from the actual wind velocity to provide three-dimensionalcalibration wind tunnel system capable of performing a simulation flightexperiment by generating a wind velocity other than that which would beencountered in flight. For example, in the case where a possible windvelocity region of the three-dimensional calibration wind tunnel systemis less than 60 m/s, the simulation flight can be experimented with thereal wind velocity as the standby speed at the time of takeoff/landingand descent in the normal airframe in the aforesaid wind velocityregion. However, the simulation flight cannot be made with the real windvelocity as the air speed greater than 60 m/s.

In view of the foregoing, in the present embodiment, an airflowgenerated by the three-dimensional calibration wind tunnel system isallowed to have the scaling function as shown in FIG. 14, and the windvelocity generated by the three-dimensional calibration wind tunnelsystem is allowed to have a continuity of specific magnification to addthe shift amount so that the simulation air flight using the truncatedpyramid-shape Pitot probe is made possible up to a speed region (lowspeed to subsonic speed) by which a similarity in the velocity vectorsis secured.

In the present embodiment, a scaling mode is set in which as shown inFIG. 14, the shift amount is set to 25 m/s, which can be continuouslyconverted into a 5-stage overspeed in which the shift amount can beadded by 1 to 5 times to the wind velocity generated by thethree-dimensional calibration wind tunnel system so that the simulationwind velocity of 180 m/s can be generated and the simulation up to theair speed of the subsonic flight can be made. In the case where theoverspeed mode is employed, the flight velocity vector detected by theair flight velocity processor 156 is converted into the velocity vectorcorresponding to the wind velocity according to the overspeed by thevelocity vector scaling function processor 161 and input into the flightsimulator computer 160. Thereby, the simulation at the time of takeoffat which particularly a change in air is great can be made even in asupersonic airframe using a small and energy saving three-dimensionalcalibration wind tunnel system, and with less simulation noise.

The flight simulator according to the present invention is constructedas described above. The simulation training of the motion performance ofan aircraft, particularly the air active control aircraft can be carriedout in three methods as follows:

First, only the flight simulator computer 160 and the simulation cockpit153 communicate, through a bidirectional communication, similarly to theconventional flight simulator, whereby the flight simulation is carriedout in the method similar to the conventional motion simulator on thebasis of the simulation software of the aircraft stored in the flightsimulator computer.

In a second method, which is a characteristic method of the flightsimulator, a flight control law is generated on the basis of the actualchange in airflow to cause a pilot to monitor motion of the aircraftcaused by the change in airflow to effect the control training. In thismethod, the flight simulator computer 160 instructs the airflowgenerator control computer 163 to generate a predetermined airturbulence whereby the three-dimensional calibration wind tunnel system1 is driven by the airflow generator control computer 163 as describedin detail in the previous embodiment to generate an airflow having apredetermined wind velocity and direction of wind. The airflow isdetected by the truncated pyramid-shape Pitot probe 155, and the flightvelocity vector is generated by the air flight velocity vector processor157. A motion simulator control signal based on a control law of theaircraft is sent by the flight simulator computer according to theflight velocity vector to the motion controller and the visualsimulation device of the cockpit to generate the motion corresponding tothe air velocity vector whereby the air flight corresponding to thechange in air can be simulated.

Therefore, according to the flight simulator of the present invention,motion based on the actual change in airflow can be generated, and morepractical flight motion can be simulated as compared with theconventional motion simulator for generating motion resulting from thechange in airflow by a simulation airflow signal which is numericallyinput. Further, air turbulence, for example, such as a gust of wind, isgenerated by the three-dimensional calibration wind tunnel system, avelocity vector based on the air turbulence is presented to a pilotwithin the cockpit, and a signal generated by the control made by thepilot is brought into engagement with a signal of the change in airflowto generate a control law whereby more practical simulation with respectto the air turbulence can be simulated.

Further, in a third method, which is more realistic than the secondmethod, a change in airflow at the time of takeoff and landing in aspecific airport is reproduced in real time or at suitable time, and themotion performance at the time of takeoff and landing at the airport ofthe air active control aircraft can be simulated on the basis thereof.That is, the aerodrome information system 165 in the airport isconnected through a telemeter or optical communication to receive airinformation (such as wind velocity, direction and altitude) generated inthe actual airport so that the same airflow as that of the airport isgenerated in real time, on the basis of which the air flight velocityvector is presented to the pilot within the cockpit to enable the flightsimulation. Training similar to that of the takeoff and landingoperation in the actual airport can be accomplished by the flight motionsimulation.

Further, the airflow information from the airport is divided, forexample, every season and every time, a number of which are stored inthe wind condition RAM 164. Specific airflow information is called fromthe RAM by the motion simulator computer when necessary to give it tothe airflow generator control computer whereby the flow generationconditions peculiar to the airport are reproduced by thethree-dimensional calibration wind tunnel system according to the seasonor time zone to enable the flight simulation training.

While in the above-described embodiment, the transportablethree-dimensional calibration wind tunnel system and the truncatedpyramid-shape Pitot probe are provided on the motion table, it is to benoted that these are not necessarily provided on the motion table butthey may be installed at a separate position away from the simulatorbody.

What is claimed is:
 1. A method of verifying a flight control system ofan aircraft on the ground on which is loaded an air flight velocityvector measuring device having an air data sensor probe in athree-dimensional true air speed detection system, wherein atransportable three-dimensional calibration wind tunnel system includesa small wind tunnel having a nozzle blow port for creating athree-dimensional calibration airflow having a suitable wind velocityand a two-axis rotational deformation device for causing the wind tunnelto effect a conical motion with the nozzle blow port serving as an apexfor suitably changing the flow angle, the nozzle blow port beingpositioned at an extreme distal end of the air data sensor probeprovided on an airframe of the aircraft, the transportablethree-dimensional calibration wind tunnel system and an on-boardcomputer being used to verify the operation and function of the flightcontrol system, wherein said verification of the operation and functionof the flight control system comprises the steps of:generating an airdisturbance with the transportable three-dimensional calibration windtunnel system on the basis of an air disturbance signal issued by theon-board control computer; detecting the air disturbance with the airdata sensor probe to thereby create a change in signal of athree-dimensional true airspeed detection system; generating controlamounts from various data bases stored in the on-board control computer;and determining whether or not each control surface angle obtained bycontrolling the amount of movement of each control surface adequatelycorrects the airframe motion due to the change in air imparted by thetransportable three-dimensional calibration wind tunnel system.
 2. Themethod of verifying a flight control system of an aircraft according toclaim 1, wherein an air flight velocity vector detected by thethree-dimensional true airspeed detection system is presented to a pilotby a monitor provided in a cockpit, and the control surface is allowedto effect motion by a signal generated by the manual operation of thepilot so as to evaluate and verify the controllability and to evaluateand verify the control characteristics including a habit of the pilot.3. The method of verifying a flight control system of an aircraftaccording to claim 2, wherein an air turbulence signal is generated bythe on-board control computer and an operation disturbance signal isgenerated whereby the evaluation and verification of the controllabilityand the evaluation and verification of the operation characteristicsincluding a habit of the pilot are accomplished.
 4. The method ofverifying a flight control system of an aircraft according to claim 1, 2or 3, wherein said aircraft is an active control aircraft with at leastone engine.
 5. The method of verifying a flight control system of anaircraft according to claim 1, 2 or 3, wherein said aircraft is anactive control aircraft without an engine in which an air flightstabilization control is made merely by the control-surface control.